Make Butter With Science

Here’s a quick and easy activity that will help you and your children understand a bit about the properties of milk and impress your friends at your next dinner party. Keep reading to learn the secrets and science behind making butter!

Here’s What You Need

½ cup heavy whipping cream
Marble or large bead
A small plastic container with a lid (I like these Rubbermaid containers)
Plastic spoon or knife
Plastic cup or bowl
Bread
Salt, honey, cinnamon sugar, or garlic salt (optional)

Here’s What You Do

Put the heavy whipping cream and the marble into the plastic container and twist on the lid. Make sure the lid is secure and begin to shake the container. You should be able to hear the marble rattling around inside.

Some people like to have some music to accompany their shaking. Here are some of my recommendations:

Occasionally open your container and observe what is happening to the cream. It begin to get thicker. After you shake for a while, you might notice that you have something very close to whipped cream in the container. Grab a quick taste if you want (it won’t be very sweet because there is no sugar in the whipped cream).

Keep shaking! After about 10-15 minutes of shaking, you should stop hearing the marble. At this point, you will need to shake the container vigorously for about 3 more minutes. Really shake it. Now, open the container and check out the results of your hard work. Your whipping cream should have separated into two parts: a thin liquid (buttermilk) and a yellow solid (butter)! Pour the buttermilk into the cup or bowl. You won’t need it now, but you may want to save it. It is great for baking.

At this point, you have sweet cream butter (great on a biscuit). If you want salted butter, you can stir in a pinch of salt. You can also add honey (honey butter), garlic salt (garlic butter), cinnamon sugar (cinnamon sugar butter), or whatever other tasty ingredient you have around the kitchen. Be creative! Now, all that’s left is to grab a knife or spoon, spread your creation on some bread, and taste it. Who knew science was so delicious?!

The Science Behind the Butter

To understand the science of butter, you first need to know a bit about milk. Most people know that nearly all of the milk we drink comes from cows. However, most people don’t know that milk is actually made up of a water-based solution and tiny globs of fat surrounded by a thin membrane. Imagine tiny balloons filled with fat floating in water. If you get fresh milk (right from the cow) and let it sit around for a while, the globs of fat will float to the top and form cream.

The milk we get from the grocery store doesn’t do this because it has been homogenized. Homogenization is a process that makes the globs of fat small enough so that they are mixed evenly in the water-based solution and do not separate in the milk. Scientists call this stable suspension of solids in a liquid a colloid. Other examples of colloids are Jell-O, shaving cream, Styrofoam, and mayonnaise.

When you made your butter, you use a marble to break the membrane surrounding the globs of fat. You basically busted the fat balloon. Soon, the cream becomes filled with tiny globs of fat. These tiny globs begin to bump into each other, stick together, and form larger and larger globs of fat. After a while, you get one, large glob of fat. We call that butter!

You might notice that your butter is slightly different color than the cream you started with. In fact, it may be yellow in color. Why is that? It is related to the diet of the cow. Cows that eat a lot of grass produce milk that is high in a chemical called carotene. Carotene is responsible for the orange-yellow color of carrots, sweet potatoes, mangos, apricots, pumpkins, and…you guessed it…BUTTER!

Fast Fact

Have you ever wondered why people made butter in the first place? The fat that makes up butter is airtight. This means that oxygen can’t easily get into the butter, and bacteria needs oxygen to grow. Without the bacteria, butter doesn’t spoil. As a result, butter tends to last much longer than the milk or cream. For people living without the convenience of electric refrigerators, this made butter very, very valuable.